From their site: The Meetup API allows developers to use the Topics, Groups and Events hosted and created on Meetup.com in their own applications and mashups. Any Meetup.com member can request an API...

Use the Social Actions Open API to search the SocialActions.com database of volunteer and philanthropy opportunities, called social actions, useful for those interested in peer-to-peer social change...

MotorsportReg.com is a membership management and event registration service for motorsport driving and social events organized by clubs, racetracks and sanctioning bodies around the world. We make it...

The Cronofy Calendar API provides a unified calendar API for all major calendar services. Rather than having to develop and maintain links to all of the calendar services your customers have chosen (...

StubHub is an online platform for people to buy and sell tickets. Users can list and sell concert tickets, sporting event tickets, and other event tickets for others to purchase and use.
The StubHub...

CashOrTrade is a platform on which users can sell, trade, or put our requests for concert tickets. The service also includes forums to organize ride-sharing, housing in concert cities, and post lost...

BeThereNYC hosts a listing for events occurring in New York City. It focuses on events taking place at museums, such as exhibitions and stargazing. It also provides a map that shows the locations of...